ES2964341T3 - Adhesive composition - Google Patents

Abstract

The present invention relates to an adhesive composition applicable to the skin comprising a base polymer comprising at least one homopolymer and/or copolymer and silica. This invention also relates to a medical adhesive device that includes said adhesive composition. The present invention relates to adhesive compositions applicable to the skin and their use in a medical adhesive device. The adhesive compositions have unique characteristics, including, for example, excellent adhesion, skin compatibility (e.g., hypoallergenicity), repositionability, substantially painless and residue-free release after application, and the ability to initiate natural antimicrobial activities. . (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Adhesive composition

field of invention

The present invention relates to adhesive compositions applicable to the skin and their use in a medical adhesive device. Adhesive compositions have unique characteristics, including, for example, excellent adhesion, skin friendliness (e.g., hypoallergenicity), repositionability, substantially painless and residue-free release after application, and the ability to initiate natural antimicrobial activities.

In particular, the present invention relates to a non-silicone based pressure sensitive hydrocolloid adhesive. The adhesive composition can be used in medical devices, particularly in skin fixation devices, wound dressings, negative pressure wound therapy (NPWT), cosmetics, transdermal delivery (TDD) and applications such as ostomy sealing. The adhesive can also be used in the manufacture of roll products, low trauma bandages and medical tapes in dressings of predetermined shape and size. Therefore, the present invention relates to the adhesive composition, its use and a method for preparing the adhesive composition.

Background of the invention

Pressure-sensitive adhesive (PSA) medical tapes and dressings/dressings are widely used for various wound care applications. Dressings differ from medical tapes in that they are cut to a selected size and shape and the adhesive is layered with a release liner/Z-fold. Medical tape and dressing basically consist of two main components, the adhesive and the backing material. The properties of both components dictate the effectiveness of the finished product. The adhesive should adhere strongly to the backing material and can be applied to the backing material by spraying the adhesive solution (organic or aqueous) or by the hot melt process. The PSA adhesive mainly comprises polymeric material, the main polymer being based on natural rubber components, synthetic rubber (copolymers of styrene-butadiene and ethylene, acrylic, silicones and/or ethylene-vinyl acetate copolymers (EVA). In addition to base polymer, the adhesive may contain other ingredients such as elastomers, rheology modifiers, fillers, water absorbers and tackifiers. The properties of the adhesive are controlled in part by varying the amount of each ingredient. Pressure is controlled in part through the adhesive and backing material—tack, adhesion, and cohesion.

Medical tape is primarily used to hold medical devices and wound/surgical dressings. As with any tape product, medical tape is typically cut or torn from a single-sided or backed roll that has at least one adhesive surface that will adhere to the skin under normal conditions without causing skin irritation, and which can be removed without any discomfort in the application area. Medical devices may include ostomy-related devices, electrodes, monitoring devices, and other accessories used in the imaging or scanning process. An ideal medical tape adhesive should adhere effectively to the surface of the skin and devices, even with gentle application, and, during its removal process, should not cause damage (including skin tearing) or irritation to the device. application area. Furthermore, the removal of the tapes should also not leave any residue, and the tape should be removed completely without leaving traces of adhesive on the applied area. Therefore, adhesive properties are mainly governed by the chemical composition or matrix of the adhesive. Additionally, certain properties of the finished product, such as moisture vapor transmission rate and elongation at break, also depend on the type of backing substrate or film on which the adhesive is laminated.

Additionally, the use of silicone-based medical tapes is not possible for some patients due to their adverse effects on the skin or the skin's tolerance level. US4505976 describes silicone-free stoma seal adhesive compositions, comprising a pressure sensitive adhesive component, a moisture absorbing component and silica.

In this context, one aspect of the invention is to provide an adhesive composition, wound dressing or ostomy product that provides good adhesion to the skin, reduces the amount of pain a patient experiences upon removal and does not leave residue. Other objects of the invention will be apparent from the following description of the invention.

Brief description of the invention

Generally speaking, the features of the invention are realized, according to one aspect of the invention, by creating a skin-applicable adhesive composition that includes a base polymer comprising at least one copolymer selected from a specified list and silica. , among other specified components. This adhesive composition has unique skin-friendly characteristics, for example, hypoallergenicity, painless removal, repositionability and leaves no residue upon removal. The present invention relates to an adhesive composition applicable to the skin comprising: (i) a base polymer comprising at least one copolymer selected from the group consisting of styrene isoprene styrene, styrene butadiene styrene, ethylene-butylene styrene, styrene- ethylenestyrene, styrene-propylene-styrene and ethylene vinyl acetate; (ii) silica; (iii) coconut oil; (iv) a mineral oil; (v) a tackifier selected from the group consisting of natural rosin, modified rosin, glycerol ester of natural rosin, glycerol ester of modified rosin, pentaerythritol ester of natural rosin, pentaerythritol ester of modified rosin, terpene resin modified phenolic, aliphatic petroleum hydrocarbon resin and cycloaliphatic resin; and (vi) a gel thickener selected from the group consisting of carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl cellulose, hydroxypropyl methyl cellulose, sodium starch glycolate, polyvinyl alcohol, polyethylene glycol, pectin, carrageenan and gelatin; wherein the composition is free of silicone; and wherein the ratio of (a) base polymer to coconut oil varies from 1:1 to 1.5:1; (b) base polymer to mineral oil varies from 0.5:1 to 0.6:1; (c) base polymer to tackifier varies from 1.3:1 to 1.7:1; (d) base polymer to silica varies from 38:1 to 78:1; (e) base polymer to gel thickener varies from 0.7:1 to 2.5:1; (f) mineral oil to coconut oil varies from 2:1 to 2.5:1.

The present invention relates to an adhesive composition that is free of silicone.

The present invention relates to an adhesive composition that includes coconut oil.

In one embodiment, the present invention relates to a medical adhesive device that includes the above adhesive composition, wherein the amount of coconut oil and mineral oil is in the range of about 48%-60% (w/w) of the total composition.

Also described herein is a method of preparing the adhesive (1) by the hot melt process wherein the individual components are combined and mixed in a heated mixer or (2) by dissolving and stirring the individual components in a suitable organic solvent. . The finished adhesive product obtained from method (1) is obtained by pressing the adhesive between two coatings or films, while that from method (2) is obtained by casting the adhesive solution on the desired film or coating and evaporating the solvent to obtain a film. thin adhesive.

Description of the figures

Figure 1 is a rheology thermogram showing the temperature ramp plot of shear modulus G'[Pa] versus temperature for adhesives prepared with and without silica.

Figure 2 is a rheology thermogram showing the frequency sweep plot of loss tangent (tan 6) versus angular frequency obtained at 37 °C for adhesives prepared with and without silica.

Figure 3 is a rheology thermogram showing the frequency sweep plot of viscosity versus angular frequency at 37 °C for adhesives prepared with and without silica.

Figure 4 is a rheology thermogram showing the effect of silica on the rheology of the adhesive.

Detailed description of the invention

The present invention relates to adhesive compositions that can be used for medical devices, particularly, for skin fixation devices, wound dressings, negative pressure wound therapy (NPWT), cosmetics, transdermal delivery (TDD) and in ostomy fixation. .

The pressure sensitive adhesive composition of the present invention differs from the above compositions in that the above compositions do not include silica. In addition to easy removal of the tape, the use of silica, for example, allows the composition to maintain its moisture content. The ease of removal is not significantly affected by the silica particle.

The pressure sensitive adhesive composition of the present invention differs from the above compositions in that the above compositions do not include reinforcing agents. These reinforcing agents are used in part to facilitate the tape removal process in addition to maintaining the moisture level of the wound.

Pressure-sensitive adhesive compositions with silica and other components have been found to exhibit unique characteristics that can be used for medical devices, particularly, for skin fixation devices, wound dressings, negative pressure wound therapy (NPWT), cosmetics , transdermal delivery (TDD) and applications such as ostomy sealing. Characteristics such as good adhesion to the skin, reasonable water absorption, low hydrocolloid thickness and easy removal without leaving any residue are obtained by varying the ratio of the different components or raw materials. The adhesive is also useful in very fragile and sensitive skin conditions.

In one embodiment, the low-trauma or skin-friendly adhesive is a complex mixture that includes an elastomer, a tackifier, a botanical fatty acid triglyceride (coconut oil), an inorganic filler (silica)/binder (e.g. cross-linked polyacrylates), a plasticizer/dispersant medium (mineral oil), a reinforcing agent and water absorbing components. The order of addition of each component is critical in determining the bulk properties and manufacturing cost of the hydrocolloid adhesive.

Each component used in the adhesive plays a definite role in improving the properties of the adhesive. The botanical coconut oil in the adhesive, in addition to acting as a plasticizer, acts as a penetration enhancer, thereby providing for the incorporation of active pharmaceutical ingredients into the adhesive, in which case the pressure sensitive tape/adhesive can be used in a transdermal delivery system. Mineral oil can serve as both a plasticizer and a solvent for the elastomer. The elastomer can be a combination of two components. The use of multiple elastomers can induce desirable properties in the adhesive and reduce the cost of the final finished product. The type and nature of the tackifier influences the tack property of the adhesive. The inorganic filling agent (silica) plays an important role in the trauma-free removal of the dressing without causing tears or damage to the patient's skin, as well as maintaining partial moisture content. The moisture absorption capacity of the adhesive can be controlled by the amount and type of moisture absorbing component in the adhesive matrix. The amount of moisture in this component/raw material also determines the moisture absorption capacity of the adhesive. The use of a reinforcing agent in the adhesive improves smooth removal of the finished product. Due to the viscous adhesive character, this formulation has a unique feature whereby the dressings can be made with low thickness of hydrocolloid.

In this present invention, the design approach is aimed at obtaining an adhesive that can be easily removed but has reasonable adhesion to the skin, prevents skin tearing, and absorbs and controls moisture levels. Due to the soft characteristics of the adhesive, it can be laminated or coated onto a backing material with any desirable thickness, usually less than 0.5 mm, and can incorporate an active pharmaceutical ingredient.

In one embodiment of the present invention, the adhesive composition comprises several types of silica, at least one reinforcing agent and at least one homopolymer and/or block copolymer. The homopolymer may include, but is not limited to, isobutylene and polystyrene.

In one embodiment, the homopolymer is a homopolymer rubber. Examples of homopolymer rubber include, but are not limited to, isobutylene, epichlorohydrin rubber, chloroprene rubber, isoprene rubber, bromobutyl rubber, and chlorobutyl rubber.

A suitable copolymer may contain at least two monomers that have very different glass transition temperatures, such that they are immiscible with each other and phase separate at room temperature. Examples of these copolymers include, but are not limited to, styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styreneethylene-butylene-styrene (SEBS), styrene-ethylene-styrene (ses), styrene -propylene-styrene (SPS) and ethylene-vinyl acetate (EVA). In one embodiment, the copolymer is selected from the group consisting of Kraton™ D 1113, Kraton™ D 1173, Kraton™ D 1107 (Shell Chemicals), Kraton™ D 1100, Kraton™ D1102, Kraton™ 4000, Kraton™ G1600, Kraton ™ G4600 and mixtures thereof. In one embodiment, the copolymer is an SIS polymer such as Kraton™ D1107 (Shell Chemicals).

In one embodiment, the copolymer is SIS. The SIS can form the base polymer that acts as a base to build the adhesive. Styrene and isoprene have very different glass transition temperatures (Tg) (+100°C and -60°C respectively). They are immiscible and phase separate at room temperature: styrene crystallizes, while isoprene remains as a liquid. Since SIS has styrene at both ends of the isoprene chains, the hardened styrene crystals act as nanoscopic physical cross-linkers and provide integrity to the adhesive, giving the adhesive mixture its cohesive strength. Isoprene, on the other hand, has a low Tg, and its Tg must be modified by an additional tackifier. Additionally, the G' of the adhesive can be modified by the addition of plasticizer, often oil or grease. Depending on the chosen oil chemistry and tackifier, they can have varying degrees of affinity toward styrene and isoprene. In general, most oils and tackifiers are chosen to have good affinity for the mid-block isoprene (I) domain and moderate to no affinity for the end-block styrene (S) domains to preserve cohesive strength. .

Suitable tackifiers often have a low molecular weight with a higher Tg than isoprene. The tackifiers are selected from natural rosin, modified rosin, natural rosin glycerol ester, modified rosin glycerol ester, natural rosin pentaerythritol ester, modified rosin pentaerythritol ester, phenolically modified terpene resin, hydrocarbon resin of aliphatic petroleum and cycloaliphatic resin.

The present adhesive compositions comprise fluid absorbent materials that are classified as hydrocolloids (HC). Hydrocolloids are used in skin fixation devices, wound dressings, negative pressure wound therapy (NPWT), cosmetics, transdermal patches, and in ostomy applications. In skin fixation and wound dressing applications, the hydrocolloid adhesive mixture is laminated to a polymer film to form an adhesive laminate. This laminate can be applied to intact skin (skin fixation) or wounds (wound dressing), acting as an environmental barrier and wound buffer, and absorbing excess body sweat and wound exudate. In the ostomy fixation system, pure hydrocolloid adhesive is pressed into a ring shape and used to attach the ostomy bag to the skin. Additionally, the adhesive can be used as a protective barrier or sealant around the stoma to prevent effluent from coming into contact with the peristomal skin.

The present compositions can be applied to medical fixation, such as IV dressing, adhesive foam and bordered foam dressings. This medical fixation will have the characteristics of painless removal and prevent damage to the periwound skin. The IV dressing is a thin clear or translucent dressing that acts as a skin barrier to cover the IV injection port. Adhesive foam is a foam dressing with an adhesive coating on the skin contact side. The adhesive allows the foam to adhere and provides a smooth bond to the wound site without the need for a nurse to apply secondary adhesive to frame the edge of the foam. The bordered foam dressing has the adhesive edge prelaminated to the foam, and the dressing is used as is, without the need for secondary adhesive.

The suitable hydrophilic fluid absorbent gum or gel thickener serves the dual purpose of absorbing moisture and providing additional cohesive strength for the adhesive composition. Suitable hydrophilic fluid absorbent gum or gel thickener provides mild tack and does not provide fluid absorption.

As used herein, the term "beneficial agent" includes any active ingredient that is to be administered in and/or on the skin, hair or nails in a desired location, such as a cosmetic agent or a pharmaceutical agent.

"Cosmetic agent" means any ingredient that is suitable for cosmetically treating, providing nutrients and/or conditioning, for example, hair, nails and/or skin by topical application.

"Pharmaceutical agent" means any drug that is hydrophobic or hydrophilic in nature and suitable for topical use.

Examples of suitable beneficial agents include, but are not limited to, analgesics, anti-inflammatory agents, both steroidal and non-steroidal in nature, antihistamines, antipruritics, general and local anesthetics, vasoconstrictors, antihypertensives including vasodilators, diuretics and ACE inhibitors, cardiac, hemostatics and styptics, mucolytics, antitussives, expectorants, mucoprotectors, antineoplastics, immunological agents, antibiotics, antivirals, antidiabetics, bronchodilators, sympathomimetics, adrenergics, adrenergic blockers, anticholinergics, antimuscarinics, antispasmodics, skeletal muscle relaxants, uterine and antimigraine drugs, sedatives, hypnotics, anxiolytics, central nervous system stimulants, antidepressants and other psychopharmaceutical agents, antiepileptics, antiemetics and hormones.

Analgesics include, but are not limited to, opiate and non-opioid analgesics and antagonists of synthetic and natural origin. Examples include, but are not limited to, morphine derivatives, codeine derivatives, methadone, propoxyphene, meperidine, fentanyl, morphinans such as levorphanol and pentazocine. Other pain relievers include, but are not limited to, acetaminophen.

Some examples of non-steroidal anti-inflammatory agents include, but are not limited to, propionic acids such as fenoprofen, ibuprofen, ketoprofen; fenamates such as meclofenamate and mefenamic acid; acetic acids such as diclofenac, etodolac, indomethacin, sulindac; oxicams such as piroxicam; and other agents such as nabumetone and oxyphenbutazone. Additionally, the following agents are also known as analgesic/anti-inflammatory agents: salicylates such as aspirin, methyl salicylate and monoglycol salicylate; salsalate; gold compounds such as auranofm; allopurinol; colchicine; and methysergide.

Examples of steroidal anti-inflammatory agents include, but are not limited to, hydrocortisone, prednisolone, dexamethasone, triamcinolone, fluocinolone, methylprednisolone, betamethasone, flumethasone, fluorometholone, beclomethasone and fluocinonide.

Antihistamines can be H1 or H2 antagonists or other types of histamine release inhibitors. H1 antagonists can be sedating or non-sedating. Examples of sedative H1 antihistamines include, but are not limited to, diphenhydramine, chlorpheniramine, tripelenamine, promethazine, clemastine and doxylamine. Examples of non-sedating H1 antihistamines include, but are not limited to, astemizole, terfenadine, and loratadine. Examples of H2 antagonists include, but are not limited to, cimetadine, famotidine, nizatidine and ranitidine. An example of a histamine release inhibitor is Cromoline.

Examples of local anesthetics include, but are not limited to, dibucaine, lidocaine, benzocaine, p-butylaminobenzoic acid-2-(diethylamino) ethyl ester, procaine, tetracaine, chloroprocaine, oxyprocaine, mepivacaine, bupivacaine, cocaine, piperocaine, and cyclonine. . Examples of vasoconstrictors include, but are not limited to, naphazoline, tetrahydrozoline, oxymetazoline and phenylephrine.

Examples of hemostatics and styptics include, but are not limited to, thrombin, phytonadione, protamine, aminocaproic acid, tranexamic acid, rutin, hesperidin, silver salts and ferric salts.

Examples of antibacterials include, but are not limited to, sulfa drugs, penicillins, cephalosporins, tetracyclines, erythromycins, aminoglycosides, polypeptide antibiotics, fluoroquinolones, chloramphenicol, clindamycin, rifampin, spectinomycin, vancomycin, bacitracin, cyclosporine, dapsone, ethambutol, ethionamide, isoniazid, nitrofurantoin, pyrazinamide and trimethoprim. Additional agents include antimalarials, amoebicides, antiprotozoals, anthelmintics, pediculicides, and scabicides.

Examples of antiviral drugs include, but are not limited to, viral DNA polymerase inhibitors such as foscarnet, protease inhibitors, thymidine kinase inhibitors, sugar or glycoprotein synthesis inhibitors, structural protein synthesis inhibitors, binding inhibitors and adsorption, amantadine and nucleoside analogues such as acyclovir, didanosine, ganciclovir, idoxuridine, ribavarin, trifluridine, vidarabine, zalcitabine, zidovudine, acyclovir, penciclovir, valacyclovir and ganciclovir.

Examples of mucolytics include, but are not limited to, potassium iodide, sodium thiocyanate, urea, guanidine hydrochloride, N-acetylcysteine, dithioteritol and proteolytic enzymes such as chymotrypsin and trypsin. These agents can be used to affect mucus production and the elasticity and viscosity of the mucus produced.

Examples of hormones include, but are not limited to, insulin, LHRH, growth hormone, calcitonin, thyroid hormones, and male and female hormones such as testosterone, estrogens, and progesterones.

Examples of astringents include, but are not limited to, aluminum salts such as alum, aluminum acetate, aluminum chloride, aluminum hydrochlorides, aluminum sulfate, aluminum zirconium hydrochloride, bismuth subcarbonate, bismuth subnitrate, calamine , glutaral, methenamine, potassium permanganate, resorcinol, silver nitrate, tannic acid, zinc caprylate, zinc chloride, zinc oxide, zinc pyrithione, zinc sulfate and zinc undecylenate.

Examples of irritants, rubifacients and vesicants include, but are not limited to, anthralin, tincture of benzoin, camphor, cantharidin, capsicum, coal tar, icthamol, juniper tar, menthol, balms such as Peruvian balm and Tolu balm.

Topical antifungals include, but are not limited to, haloprogin, cyclopirox, flucytosine, miconazole, econazole, clotrimazole, fluconazole, oxiconazole, sulconazole, metronidazole, itraconazole, ketoconazole, butaconazole, terconazole, nystatin, povidone-iodine, tolnaftate, benzoic acid, salicylic acid, mercuric oxide, resorcinol, triacetin, undecylenic acid and its calcium, copper and zinc salts.

Topical anesthetics include, but are not limited to, the local anesthetics described above and benzyl alcohol, camphor, camphorated metacresol, juniper tar, menthol, phenol, sodium phenolate, resorcinol, methyl salicylate, turpentine oil, camphor, menthol , methyl nicotinate, capasaicin, capsaicin containing capsicum and capsaicin containing capsicum oleoresin.

Examples of keratolytic and cauterizing agents include, but are not limited to, salicylic acid, podophyllium resin, podolifox, cantharidin, chloroacetic acids and silver nitrate.

Examples of topical bactericides and disinfectants include, but are not limited to, thimerosal, phenol, thymol, benzalkonium chloride, benzethonium chloride, chlorhexidine, povidone iodine, cetylpyridinium chloride, eugenol and trimethylammonium bromide.

Short-chain fatty acids (SCFAs) are fatty acids with aliphatic ends of less than six carbons. Short chain fatty acids useful in the practice of the present invention include, but are not limited to, acetic acid, propionic acid, isobutyric acid (2-methylpropanoic acid), butyric acid, isovaleric acid (3-methylbutanoic acid), valeric (pentanoic acid) and caproic acid (hexanoic acid).

Medium chain fatty acids (MCFAs) are fatty acids with aliphatic ends of 6-12 carbons. Medium chain fatty acids useful in the practice of the present invention include, but are not limited to, caproic acid (C6), caprylic acid (C8), capric acid (C10) and lauric acid (C12). In one embodiment of the invention, coconut oil, which is a mixture of 2(C6):55(C8):42(C10):1(C12), is a source of fatty acids.

Long-chain fatty acids (LCFAs) are fatty acids with aliphatic ends of more than 12 carbons. Long chain fatty acids useful in the practice of the present invention include, but are not limited to, myristic acid (14 carbons), palmitic acid (16 carbons), oleic acid (18 carbons - monounsaturated), stearic acid (18 carbons - saturated) and erucic acid (22 carbons). In one embodiment of the invention, myristic acid and palmitic acid are preferred long chain fatty acids.

Very long chain fatty acids (VLCFAs) are fatty acids with aliphatic ends of more than 22 carbons. Very long chain fatty acids may be useful in the adhesive compositions of the present invention.

Essential fatty acids useful in the practice of the present invention include, but are not limited to, alpha linolenic acid, eicosapentaenoic acid, docosahexaenoic acid and gamma linolenic acid. In one embodiment of the invention, alpha linolenic acid and eicosapentaenoic acid are components of the adhesive compositions of the present invention.

To obtain excellent uniformity in the adhesive, fillers or reinforcing agents with high surface area are used as components in the adhesive compositions of the present invention.

Suitable hydrophilic liquid absorbents or gel thickeners are selected from naturally occurring hydrocolloids, semisynthetic hydrocolloids and synthetic hydrocolloids.

Hydrocolloids useful in the practice of the present invention include, but are not limited to, water absorbent and/or water swellable material such as carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl cellulose, hydroxypropyl methyl cellulose, glycolate sodium starch, polyvinyl alcohol, polyethylene glycol, pectin, gelatin, high molecular weight carbowax, carboxypolymethylene, carboxymethyl starches, alginates, carrageenan, gelatin, citrus pectin, powdered pectin, synthetic or natural gums, such as guar gum, gum arabic, locust bean gum, karaya and mixtures thereof.

In one embodiment of the invention, the wound dressing may contain elastomeric binders and tackifiers.

Elastomeric binders useful in the practice of the present invention include, but are not limited to, diblock, triblock or multiblock elastomeric copolymers such as olefin copolymers (e.g., styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-ethylene/ butylene-styrene and styrene-ethylene/propylene-styrene). Examples of elastomeric binders include those available from Shell Chemical Company, under the trade designation KRATON® elastomeric resin; polyurethanes, such as those available from E. I. Du Pont de Nemours Co., under the trade name LYCRA® polyurethane; polyamides, such as polyether block amides available from Ato Chemical Company, under the trade name PEBAX® polyether block amide; or polyesters, such as those available from E. I. Du Pont de Nemours Co., under the polyester trade name HYTREL®; natural rubbers, silicone rubber, polyisobutylene rubber and acrylonitrile rubber. In an exemplary embodiment, KRATON® olefinic copolymers are used in the adhesive compositions of the claimed invention.

A tackifier is used to control the tack of the adhesive and reduce the moduli and increase the glass transition temperature. The tackifying agents according to the invention are natural rosin, modified rosin, glycerol ester of natural rosin, glycerol ester of modified rosin, pentaerythritol ester of natural rosin, pentaerythritol ester of modified rosin, modified phenolic terpene resin, aliphatic petroleum hydrocarbon resin and cycloaliphatic resin. Representative tackifiers, known by their trade names, are Kristalex™ 3085, FORAL® 85 and ARKON®P115. Kristalex™ 3085 and FORAL® 85 are hydrocarbon tackifiers. ARKON® PI 15 is a hydrogenated hydrocarbon tackifier. In one embodiment of the invention, Kristalex™ 3085 is used as a tackifier.

In one embodiment of the present invention, the adhesive composition comprises a botanical penetration enhancer. The botanical penetration enhancer is coconut oil. Coconut oil can be dehydrogenated or hydrogenated.

In one embodiment of the present invention, the adhesive composition comprises silica and at least one copolymer, a botanical penetration enhancer, a tackifier and a gel thickener.

In one embodiment of the present invention, the adhesive composition comprises silica and at least one copolymer, a tackifier, a filler, an inhibitor and one or more stabilizers.

In one embodiment, the present invention relates to an adhesive composition comprising a mineral oil and optionally a plasticizer selected from the group consisting of citrate oil, paraffin oil, phthalic acid esters, adipic acid esters, liquid resins. or solids and mixtures thereof.

In another embodiment of the present invention, the adhesive composition comprises other ingredients, including, for example, antioxidants, stabilizers, fillers, pigments, flow modifiers and active ingredients such as drugs. The filling agent or reinforcing material may be silica, which is treated or untreated, complexed or chelated.

In one embodiment, the present invention relates to a pressure sensitive adhesive composition for skin application comprising 15-25% (w/w) based on the total blend formulation of a mixture of at least one homopolymer and/or copolymer , for example, polystyrene-isoprene-polystyrene or polystyrene-isoprene-butadiene and silica/polyacrylate.

In one embodiment, the present invention relates to a pressure sensitive adhesive composition wherein the mixture of copolymer and silica is less than 15% (w/w) of the total mixture formulation, and the content of the homopolymer and copolymer is less than 30% (w/w) of the total mixture formulation.

In one embodiment, the present invention relates to a pressure sensitive adhesive composition for skin application comprising 15-25% (w/w) based on the total blend formulation of a mixture of at least one homopolymer and botanical oil.

In one embodiment, the present invention relates to a pressure sensitive adhesive composition for skin application comprising 50% botanical oil based on plasticizer content.

In one embodiment, the final adhesive in continuous form exhibits a water absorption rate of 13%/24 hours at 37°C.

In one embodiment, the final adhesive has a complex modulus G' of less than 20,000 Pa. In one embodiment, the final adhesive has a complex modulus G' of less than 30,000 Pa at 1 Hz (1% strain, 32°C) .

In one embodiment, the final adhesive has a tan(S) greater than 0.2. In one embodiment, the final adhesive has a tan(S) greater than 1.6 at 1 Hz (1% strain, 32°C).

In one embodiment, the content of the adhesive mixture comprises a tackifier resin such as natural, modified or synthetic resins.

In one embodiment, the tackifier resin content is 0-25% (w/w) of the final adhesive. In one embodiment, the content of the tackifier resin is 5-20% (w/w) of the final adhesive. In one embodiment, the tackifier resin content is 7-15% (w/w) of the final adhesive.

In one embodiment, the composition further comprises other ingredients, including, for example, stabilizers, fillers, pigments, flow modifiers and active ingredients.

In one embodiment, the composition further comprises one or more absorbent particles such as a cellulose hydrocolloid.

In one embodiment, the cellulose hydrocolloid content is about 5-25% (w/w) of the total composition.

In one embodiment, the composition further comprises one or more reinforcing agents and water absorption modifiers.

In one embodiment, the present invention relates to a low trauma tape comprising a pressure sensitive adhesive composition comprising a mixture of at least one homopolymer and/or copolymer and one or more silica/polyacrylate compounds.

In one embodiment, the medical tape can be used for skin fixation applications, such as catheter fixation, medical devices, and ostomy seals.

The invention is illustrated in more detail in the following examples describing embodiments of the invention.

EXAMPLES

In one embodiment, the adhesive compositions of the present invention are prepared according to the following methods.

An adhesive composition was prepared by the hot melt process by adding the base polymer to a heated mixer in which the temperature in the mixer was set at 180°C and the temperature measured inside the mixer was between 110-120°C. The base polymer was allowed to rotate in the mixer for 5-15 minutes or until the base polymer showed coarse particles. The plasticizer was then added in small aliquots to obtain a uniform smooth mass. The mixture was allowed to rotate for 5-15 minutes. The set temperature was then reduced so that the temperature inside the mixer was between 100-110°C. At this point, small amounts of the penetration enhancer or botanical component were added. To reduce processing time, it was necessary to add the plasticizer before adding the penetration enhancer. At this point, the filler component of the mixture was added, followed by the tackifier and water absorbent. The temperature inside the mixer was reduced to between 90-100 °C before the addition of the water absorbent. To obtain content uniformity in the adhesive, the mixture was allowed to tumble for at least 10 minutes before adding the next component. At the end of the mixing process, the adhesive was poured and allowed to cool to room temperature before manufacturing the finished product.

An alternative method of preparing the adhesive is by dissolving each component of the adhesive in an organic solvent such as toluene or heptane. In order to achieve complete solubility of each component, the mixing solution was stirred at room temperature for approximately 24 hours. The stirring time can be reduced if the stirring was performed at a higher temperature. At the end of the mixing period, the adhesive solution is poured onto the desired film and the solvent is evaporated to obtain an adhesive of the desired thickness.

Example 1: Representative components used in the adhesive composition of the present invention.

Table 1

Example 2: Representative composition according to an aspect of the present invention.

Table 2

Example 3: Representative composition according to an aspect of the present invention. sf04261 has the same composition as MA05172 but without Aerosil 200.

Table 3

Example 4: Representative compositions according to an aspect of the present invention. The adhesive compositions were prepared with different types of silica or filling agent.

Table 4

Example 5: Representative compositions according to an aspect of the present invention. The adhesive compositions were prepared with the same composition as MA05172 but with a base polymer of Styrene-Isoprene-Butadiene-Styrene (SIBS) and a mixture of copolymers.

Table 5

Example 6: Representative compositions according to an aspect of the present invention. The adhesive compositions were prepared with different fillers/concentration of water absorbing species. These compositions were characterized by their water absorption property.

Table 6

Example 7: Composition test by measuring water absorption

A. Sample pressing conditions and procedure:

A small portion of the adhesive was pressed between a clear silicone liner using a compressor mold at 85°C and a force of 8000 lb, dwell time of 8 seconds with a thickness of 1 mm. The sample was prepared by drilling a 1' diameter circle and the water absorption was determined according to the Euromed Inc. method.

B. Method for determining water absorption

The sample with the transparent silicon coating was weighed. The transparent silicon coating was removed and weighed. Next, the weight of the sample (Wo) was determined. The sample was then immersed in a tray well containing 0.9% saline in a 37°C oven. The sample was weighed at the desired time (Wt) and the % water absorbed was determined as shown below. % o f water absorbed = ([W t - W q]/W q) *>100

C. Results

7.1.Water absorption for the adhesive composition at 3 time points

Table 7.1

7.2.Water absorption for the adhesive composition at 2 time points

Table 7.2

7.3.Water absorption for the adhesive composition at 6 time points

Table 7.3

Example 8:Clinical example

The wound dressing composition of the present invention is effective in treating the following example conditions:

Yo. Chronic and acute wounds, moderate to heavy exudation, partial and full thickness, including superficial wounds

ii. Second degree burns

iii. Pressure ulcers, stages II -IV

Example 9: Meaning of silica in the adhesive composition

a) Comparison of the shear modulus G'[Pa]

For wound dressings, the adhesive is often formulated to be soft and gentle, which is characterized by the low adhesive shear storage modulus G'[Pa]. The temperature ramp plot of shear modulus G'[Pa] versus temperature for adhesive compositions prepared with and without silica shows some differences in G' (see Figure 1 and Table 8).

Table 8

The G' for the silica-containing adhesive is an order of magnitude smaller than the non-silica adhesive. Between 20 and 30 °C, the decrease in % shear modulus for the adhesive with SiO2 was greater than that for the adhesive without silica. The low G' value for the SiO2 adhesive at ambient conditions indicates the soft characteristics of the adhesive, which is a critical requirement for the adhesive to be used in low-trauma applications. The temperature at which tan 8 = 1 was higher for the adhesive without SiO2 (86.3 versus 63.3 °C) indicates the stiffness of the adhesive. Additionally, application of the silica-free adhesive left a residue upon removal and was slightly aggressive.

b) Comparison of loss tangent (tan 8)

Frequency sweep plot of loss tangent (tan 8) versus angular frequency was obtained at 37 °C for adhesives prepared with and without silica. At 37°C, from 0.1 to 50.0 rad/sec, tan 8 was lower for the adhesive with SiO2, indicating better viscous characteristics of the adhesive (see Figure 2).

c) Comparison of viscosity.

The frequency sweep plot of viscosity versus angular frequency was obtained at 37 °C for adhesives prepared with and without silica. The viscosity at 37°C for the adhesive with S O 2 was more linear compared to the adhesive without SiO2, indicating for the above adhesive that the storage modulus (G') and the loss modulus (G") are independent of the frequency and the silica and CMC particles are uniformly dispersed in the adhesive matrix (Figure 4). Therefore, this demonstrates the importance of silica in the adhesive as a rheology modifier and softening agent in the designed application range. .

Claims (7)

1. An adhesive composition applicable to the skin that comprises: (i) a base polymer comprising at least one copolymer selected from the group consisting of styrene-isoprenestyrene, styrene-butadiene-styrene, styrene-ethylene-butylene-styrene, styrene-ethylene-styrene, styrene-propylenestyrene and ethylene-acetate vinyl; (ii) silica; (iii) coconut oil; (iv) a mineral oil; (v) a tackifier selected from the group consisting of natural rosin, modified rosin, glycerol ester of natural rosin, glycerol ester of modified rosin, pentaerythritol ester of natural rosin, pentaerythritol ester of modified rosin, terpene resin phenolically modified, aliphatic petroleum hydrocarbon resin and cycloaliphatic resin; and (vi) a gel thickener selected from the group consisting of carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl cellulose, hydroxypropyl methyl cellulose, sodium starch glycolate, polyvinyl alcohol, polyethylene glycol, pectin, carrageenan and gelatin; wherein the composition is free of silicone; and where the relationship of (a) the base polymer to coconut oil varies from 1:1 to 1.5:1; (b) base polymer to mineral oil ranges from 0.5:1 to 0.6:1; (c) base polymer to tackifier varies from 1.3:1 to 1.7:1; (d) the base polymer to silica varies from 38:1 to 78:1; (e) base polymer to gel thickener ranges from 0.7:1 to 2.5:1; (f) mineral oil to coconut oil varies from 2:1 to 2.5:1. 2. The adhesive composition of claim 1, wherein the silica compound is fumed silica. 3. The adhesive composition of claim 1, wherein the amount of the mineral oil is in the range of 22%-44.9% (w/w) of the total composition. 4. The adhesive composition of claim 1, wherein the amount of the gel thickener is in the range of 1.8%-19.2% (w/w) of the total composition. 5. The adhesive composition of claim 1, wherein the amount of the base polymer is in the range of about 14%-28% (w/w) of the total composition, and wherein the amount of silica is in the range of 0 .2%-9.4% (w/w) of the total composition. 6. The adhesive composition of claim 1, wherein the amount of the coconut oil is in the range of about 10%-21.5% (w/w) of the total composition. 7. A medical adhesive device comprising the adhesive of claim 1, wherein the amount of coconut oil and mineral oil is in the range of about 48%-60% (w/w) of the total composition.